JPS6113966A - Capillary tube dialyzer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a generally tubular casing and a blood cell which is secured within the casing by an embedded material on both sides and is sealed to each other and to the casing. One inlet chamber and one outlet chamber each for connecting a bundle of capillary tubes each terminating in one end face, and having two casing-side connections and surrounding the capillary tubes between the buried material. The present invention relates to a capillary dialyzer comprising a dialysis chamber formed in a dialysis chamber.

Such a capillary dialyzer corresponds in its structure and embodiment to the conventional design and embodiment.

PRIOR ART Capillary dialyzers with a casing having a tubular cross section are known to contain bundles of capillary tubes, i.e. extremely fine tubes with an internal diameter of about 0.2 mm and a wall thickness of 5 to 20 μm. It is made by inserting it into a casing with a tubular cross section. The ends of the tubular cross-section casing are each closed with a cover cap. Embedded material through connections for dialysate in both end areas
-' is inserted between the capillary bundle and a casing with a tubular cross section. Due to the centrifugal movement of the casing with tubular cross-section about its central transverse axis, the buried material is distributed between the capillaries and between the capillaries and the casing wall, filling the space up to the cover cap. It will be done. The embedded material then solidifies, thereby simultaneously fixing and sealing the capillary tube within the casing having a tubular cross section. After the cover cap, which is necessary only for the injection of the implanting substance, has been removed, the bundle of capillary tubes inserted into the casing, which originally has a corresponding length and a tubular cross section, is cut off on both sides. This cutting can also be done by punching. This cut results in an end face that passes through the capillary tube and the buried material and ends in the vicinity of the casing wall. However, this cutting disadvantageously results in roughness of the end face, both in the region of the buried material and also in the region of the capillary end. Also, the capillary tubes themselves often have cracks in their tube walls, which disadvantageously tend toward the inner chamber, which are usually formed by the tube walls of the individual capillaries. This crack can be confirmed when the cut surface is enlarged and observed using an electron microscope.

Separation phenomena between the capillary wall and the buried material are also observed. The above roughness acts as a lysate or a bacterial cell,
Their shape and presence increase the risk of blood coagulation occurring when using a capillary dialyzer. As a result of this coagulation phenomenon, the individual capillaries become occluded on the inlet side, ie in the region of the inlet chamber. As a result, the dialysis surface of the dialyzer is reduced due to clogging of the capillaries. The required dialysis rate can therefore no longer be achieved. Another disadvantage is that the patient suffers a corresponding blood loss. This is because the possibility of blood purification is not obtained due to capillary clogging.

OBJECT OF THE INVENTION The object of the invention is to provide a method of the type described at the outset, which eliminates the above-mentioned disadvantages and which, when used, reduces the lack of capillary action and the consequent blood loss of the patient. To build a capillary dialyzer.

'Means for Solving the Object The above-mentioned object is solved according to the invention in that at least one of the end faces of the buried material and the capillary tube has a laminate.

The application of this laminate to the cut end face of the working potting material and the capillary tube results in smoothing and rounding of the surface. The damage to the surface of microscopic units induced by cutting is smoothed out. Foreign material is contained, cracks are filled, and overall surface roughness is reduced, so that the risk that such rough locations trigger blood clotting is significantly reduced. Of course, the lamination is carried out in such a way that the capillary opening of the capillary tube is not overstrained or covered by the lamination. Capillaries of course have to remain open because blood flows through them. However, it is entirely possible to carry out the lamination all the way around the inner edges of the individual capillaries to the extent that the inner walls of the capillary tubes form, thereby rounding out even the sharp edges inside each capillary tube. And it's also advantageous.

This K results in favorable geometrical conditions at the inlet to the individual capillary tubes in terms of the intended blood flow.

A laminate made of polyurethane is particularly suitable, the capillary being made of regenerated cellumose. The polyurethane adheres to the cellulose and does not peel therefrom even when wetted by liquid.

However, the laminate, which is generally formed extremely thin and thus satisfies the smoothing and flattening functions, is made of a material that has a porous filter structure and allows the accumulation of protein substances generated from blood. You can leave it there. This results in a unique surface that is particularly well compatible with blood due to the accumulation of unique protein substances originating from the blood, yet also compatible with any patient. Of course, these aspects occur initially during use of the dialyzer, but by using a laminate of porous filter structure types.

Possibilities for such embodiments can be obtained.

Such a porous filter structure is obtained, for example, if the stack consists of a synthetic material dissolved in two solubilizing agents, in which case the evaporation properties of these two solubilizing agents are different.

After forming the laminate, first the solvent 1 evaporates and the concentration of the synthetic substance in the solvent 2 increases. Before the solvent 2 evaporates, a locally different precipitation step takes place, in which case the desired porous filter structure is formed. Finally, the solvent 2 is also completely evaporated. A laminate is formed from two layers, the first of these layers being used as an adhesion base layer for the second laminate,
It is also possible to form the second laminate according to the structure set forth in claim 4. Therefore, the first laminate actually fulfills the smoothing and flattening functions, while the additional second layer of the laminate formed on top of the first laminate has a porous filter structure. form. It is also possible to provide the laminate on the surface of the entire inlet or outlet chamber. However, only laminates with a porous filter structure are used for this purpose, since the surfaces of the inflow and outflow chambers are formed by parts of the housing cover that are not subjected to cutting or punching operations. of course,
It is also possible to provide this (second) laminate with a porous filter structure only on the buried material and on the end faces of the capillary tube. Laminates with filter structures are essentially made of polysulfone, polyamide, polymethyl methacrylate, polycarbonate or cellulose acetate.

The first laminate has a wall thickness of approximately 5-20 μm, and the second laminate has a wall thickness of approximately 5-50 μm.

If the stack is thin in this way, there is no risk that the individual capillaries will become clogged or become inescapably narrowed due to the formation of the stack.

It is a feature of the invention that the risk of blood coagulation is reduced by providing a laminate on the cut ends of the capillary tube and the embedded material of the capillary dialyzer. I can say it.

The invention will be explained in more detail below with reference to embodiments illustrated in the accompanying drawings.

The capillary dialyzer shown in FIG. 1 comprises a casing 1 of tubular cross-section, in which a plurality of bundles of capillary tubes 2, shown extremely enlarged in FIG. 1, are provided. At both ends the bundle of capillary tubes 2 is embedded in an embedding material 3. This embedded material not only fixes the bundle of capillary tubes 2 within the casing 1, but also seals the capillary tubes 2 from each other and against the wall of the casing 1. The buried material 6 and the capillary tube 2 end at an end face 4. The ends of the tubular cross-section casing 1 are provided with outer walls 5 2, on which a cover 6 is provided in each case under a not-shown interposition of a sealing body. This cover 6 is provided with a connecting pipe 7 for connecting a hose conduit.

In this manner, one end of the casing has an inlet chamber 8.
However, an outflow chamber 9 is formed at the other end. Both chambers 8 and 9 are of essentially the same or similar design, so that the capillary dialyzer can be used in any orientation.

Of course, the blood flows into the inlet chamber 8 via the connecting tube 7, from there it is distributed onto the capillary tubes 2 and flows through them. The blood collects from the individual capillary tubes 2 in the outflow chamber 9 and flows out again via the connecting tube 7.

Internal chamber 1 formed between capillary tubes 2 between buried substances 3
0 is for dialysate. The dialysate flows through the two connecting tubes 11 and 12 in the direction of arrow 13, while the blood flows in the direction of arrow 14. A laminate 15 is placed on the end surface 4.
is provided, and this laminate extends over the entire width of the buried material 5 and encompasses the four sides of the capillary tube 2.

The laminate 15 forms a surface that is compatible with blood/liquids, which helps reduce roughness, encapsulate foreign materials, and round out sharp materials, thus significantly reducing the risk of blood clotting overall.

Figure 2 clearly shows the working steps in the process of making a capillary dialyzer. In this case, after the somewhat longer capillary tube 20 bundle has been inserted into the casing 1, the tubular cross-section of the casing 1 is replaced by a special cover cap 1 instead of by the cover 6.
It is closed at 6.

The connecting pipe 1 is inserted into the buried material 3 while it is not yet hardened.
It will be introduced after 1 and 12. Subsequently, the casing thus prepared is rotated multiple times by centrifugal movement about its central transverse axis. In this case, the intermediate chamber between the end cover cap 16 of the casing is filled with potting material, which hardens in this working stage. Of course, the buried material 6 extends to an extent, viewed inwardly from the end face of the casing 1, into the casing and thus the capillary 2
In the end face area of the casing 1 this solid and gas-tight connection is formed.

After curing, the cover cap 16 is removed and the knife 1 is inserted so that the excess embedded material 3 is cut off along with the end of the capillary tube 2.
7 or cutting by a punching device. During this cutting, in this stage an end face 4 is produced on each side with a significant surface roughness. Cracks are often observed between the buried material 6 and the end of the capillary tube 2. The capillary portion also hangs down into the internal space of the capillary in the form of a tuft. All these roughnesses create a risk of blood clotting during use. Here, the roughness on the order of microμ is eliminated by the laminate 15 (FIG. 3), and the surface is flattened and smoothed. From FIG. 3, which is shown in extreme enlargement, it can be seen how the laminate 15 extends around the inner edge 18 of the end of each capillary tube 2, and also around the inner edge 18 of the end of each capillary tube 2.
It is observed that the sharp inner edge 18 extends to a depth such that the sharp inner edge 18 is rounded in any case. The thickness of this laminate 15 is in the range of 5 to 20 μm. The laminate 15 has a smooth and flat surface 19 to which blood components do not adhere. This laminate 15
Polyurethane is particularly suitable for this purpose. capillary tube 2 on one side
consists of regenerated cellulose. Polyurethane adheres particularly well to cell a-ss and does not peel off when wetted by liquids. Instead of the laminate 15 with a smooth surface 19, it is also possible to form a laminate 2o with a porous filter structure on the end face 4.

FIG. 4 shows that it is also possible to form the stacks 25 and 20 one after the other, ie in the form of two layers one above the other. This porous filter structure serves to create a substrate for the accumulation of proteinaceous substances from the blood such that the surface is generally both affinity and permissive for blood. It is possible to form the stack 20 with a porous filter structure not only on the end face 4 but also on the surfaces of the inflow chamber 8 and the outflow chamber 9, ie essentially on the inside of the cover 6. A design on the inlet side is particularly advantageous.

The laminate resulting in the porous filter structure generally consists of two synthetic materials dissolved in a solvent with different evaporation properties. In this case it is advantageous to use the following proportions: 7.5 g of polycarbonate are used as synthetic material. This polycarbonate is dissolved in 92.5 g of methylene chloride with a fast evaporation rate as the first solvent. Additionally, this synthetic material has a relatively slow evaporation rate as a second solvent.+2.
5 i of dimethylene acetamide. It is also possible to use dimethylformamide instead of dimethyleneacetamide. After forming such a laminate 2o, first the first solvent, methylene chloride, evaporates, and the concentration of the synthetic substance in the second solvent, namely dimethylacetamide, increases. When the second solvent, dimethylacetamide, evaporates, localized precipitation takes place and a porous fibrous structure is formed. The second solvent is then completely evaporated.

[Brief explanation of drawings]

1 is a sectional view of a capillary dialyzer; FIG. 2 is a sectional view of the end region of a capillary dialyzer before cutting; FIG. 6 is a sectional view of the end of an individual capillary tube with a simple stack. Figures 2 and 4 are cross-sectional views of the ends of individual capillaries with first and second laminates. The symbols in the figure are 2... Capillary tube 3... Buried material 4... End face 15. 20... Laminated body

Claims (1)

[Claims] 1. A generally tubular casing and an inlet chamber for blood, each of which is secured by an embedded material on both sides and sealed to each other and to the casing; a bundle of capillary tubes each terminating in one end face with which the outflow chamber is connected, and a dialysis chamber having two casing-side connections and formed around the capillary tubes between the embedded materials; In the capillary dialyzer, at least one end surface of both end surfaces (4) consisting of the buried material (5) and the capillary tube (2) is connected to the laminate (1).
5, 20). 2. The capillary tube according to claim 1, wherein the laminate (15) is provided to a certain depth along the inner wall of each capillary tube (2) around the inner edge of each capillary tube (2). Dialyzer. 3. The laminate (15) is made of polyurethane and has capillary tubes (
2) A capillary dialyzer according to claim 1 or 2, wherein 2) is made of regenerated cellulose. 4. The capillary dialyzer according to claim 1, wherein the laminate (20) has a porous filter structure and is made of a material that allows accumulation of protein substances discharged from the blood. 5. Capillary dialyzer according to claim 4, in which the laminate (20) with the porous filter structure consists of two synthetic substances dissolved in solvents with different evaporation properties. . 6. The capillary tube according to claim 4 or 5, wherein the laminate (20) having a porous filter structure is formed on the surface of all inflow chambers or outflow chambers (8, 9). Dialyzer. 7. The laminate (15, 20) consists of two layers, and the first layer formed among these layers is the second laminate (20)
Claims 1 to 3, in which the second laminate (20) is provided with a porous filter structure and consists of a material that allows the accumulation of protein substances from the blood. The capillary dialyzer according to any one of items 3 to 3. 8. According to claim 7, the first laminate (15) has a wall thickness of about 5-20 μm and the second laminate (20) has a wall thickness of about 5-50 μm. capillary dialyzer. 9. According to claims 4 to 8, the laminate (20) with porous filter structure consists essentially of polysulfone, polyamide, polymethyl methacrylate, polycarbonate or cellulose acetate. Capillary dialyzer as described.